* Draft version of the Swish nGraph operation and fusing transformations for different approaches to express the operation
* Swish fusing transformation refactoring
* Added Swish operation and extractor for TF. Removed unfolding transformation for the operation.
* Added SwishIE. Implemented transformation to convert Swish to SwishIE.
* Code style fixes
* Updated Swish reference implementation. Added tests for shape and value inference
* Fixed code style for Python API
* Fixed unit test
* Apply review comments
* Use matcher_pass_callback
* Make m_alpha attribute protected in the SwishIE operation
* Fixed Swish op PythonAPI test
Alexey Suhov